Phenom II X4 for socket AM3 reviewed: Phenom with DDR3-RAM

AMD completes the Phenom II series with five new middle-class CPUs which have one important feature: socket AM3 for DDR3-RAM. PC Games Hardware tests the new processors.

Two of the five new CPUs: Phenom II X3 720 BE (left) and Phenom II X4 810 (right) [Source: view picture gallery]

"AMD is back”: That has been our conclusion after our Phenom II review, since the processor brought AMD back on the same level as Intel's Core 2 Quad - at lower prices. But only some weeks later AMD takes the next step and launches another CPU: the Phenom II for the socket AM3 inclusive DDR3 support.

Retrospect: AMD Phenom IIThe Phenom II X4 with the codename Deneb succeeded the first quad-core Phenom generation, also known as K10 or Agena. The transition from 65 to 45 nanometer technology lowered costs and power consumption and was supposed to make higher frequencies possible. The L3 cache increased from 2 to 6 MiByte. The first two Phenom II models were the X4 940 BE with 3 Gigahertz and the X4 920 with 2.8 Gigahertz - so both were running at a higher frequency than the fastest of the original Phenoms, the X4 9950 BE with 2.6 GHz. Due to this improvement, and several others of course, the 940 BE reached the performance of the more expensive Core 2 Quad Q9550. As a socket AM2+ processor the Phenom II fit into many already available motherboards and used DDR2 only- until now.

Phenom II X4 810 (AM3) [Source: view picture gallery]

Phenom II, second takeDDR 3 support is one of the most obvious new features that have been delivered by AMD. Intel's Core 2 had been able to deal with the new standard for quite some time, if combined with the right chipset and the controller of the Core i7 can only work with DDR3. Now the Phenom II draws level: The five new models from the X3 710 to the X4 910 (see chart below) are now compatible to DDR3 memory. But this only works if a AM3 motherboard is used - if the processors are placed on an AM2+ socket, then they still have to be combined with DDR 2 and wouldn't differ much from the pure AM2+ models 920 and 940 BE.

This is what AMD intended: In contrast to the new processors, AMD did not yet introduce the socket AM3 officially and this probably won't happen until March or even late. Therefore AMD recommends that tests are run on proven AM2+ boards. But this would make possible benefits from DDR3 useless, so we ran most of our tests on an AM3 board with DDR3 RAM. The boards are final and big performance benefits from new BIOS versions are not expected - but our results nevertheless have to be seen as an AM3 preview. For comparison we also tested the X4 810 on a AM2+ board with DDR2 and thus check the advantages of the more expensive DDR3 RAM (see Cinebench results).

AMD introduces five new CPUs - two of them are for the retail market. [Source: view picture gallery]

Phenom II AM3: The new CPU in detailAMD releases five new processors: Below the X4 940 BE and the 920 there is the Phenom II X4 910 with 2.6 GHz. The new 800 series is intended for the quad-core entry level with the X4 810 (2.6 GHz) and the 805 (2.5 GHz) - in contrast to the 900 series they only have 4 MiByte L3 cache but this shouldn't really matter in games. All new cores have the Deneb architecture - like the new X3 triple-core even if got the codename Heka. Inside there are only three active cores so that it has to work with 3x 512 MiByte L2 cache. But it has access to the full 6 MiByte L3 cache. In the form of the 720 BE with an open multiplier it works with 2.6 GHz, the 710 as the smallest newcomer runs at 2.5 GHz. Later there are likely to be dual-core versions, but they will probably be (like the X2 7750 BE) called Athlon.

For all new processors AMD increased the frequency of the Hypertransport interfaces again, from 1,800 (Phenom II AM2+) to 2,000 MHz which had also been used for the former top model 9950 BE; but the faster link to the motherboard chipset doesn't promise a better performance. Otherwise the architecture of the Phenom II is unchanced.